The present invention relates to coil winding machines.
In many instances of coil winding, especially in toroidal coil windings, the relationship between a coil and the shuttle which performs the winding of a filament about the core are not always symmetrical. Usually in these types of machines, the shuttle rotates about the core at a constant rate during each turn pulling the filament from a floating rotatably mounted magazine. The magazine usually includes tension devices which provide slip-clutch rotary braking action in a direction reverse to the direction to which the filament is pulled from the magazine. In effect, the magazine is rotated in the direction opposite of the shuttle so as to maintain tension on the dispensed filament.
Due to the asymmetrical spaced relationship between the shuttle and magazine to the coil, the amount of wire pulled from the magazine by the shuttle during each turn of the coil varies in accordance with the angular position of the shuttle with respect to that coil. To compensate for this asymmetrical condition, the tension devices provided at the magazine need to provide sufficient braking action so as to maintain the desired tension on the filament regardless of the variations in tension exerted on the filament then being dispensed. This action usually results in abrupt changes in motion of the magazine causing jerking of the filament, and in some instances, breakage of the filament. To prevent this undesirable condition from arising, the shuttles are operated at that maximum speed below which breakage of filament no longer occurs. This maximum speed is usually much less than the machine capability and therefore reduces the machine efficiency.